In the primary oil systems of flight propulsion gas turbine engines, centrifugal force is often employed to induce primary oil flow to rotor shaft bearings. For example, oil may be sprayed from a stationary nozzle onto a tapering inside wall of the rotating shaft. Centrifugal force holds the oil on the surface and induces the oil to flow in a direction determined by the taper of the wall to an orifice through the wall. The oil migrates radially out through the orifice to a bearing. In one such system having two parallel flow paths, one of the flow paths is inactive except when the other flow path is blocked. In such systems, generally, if primary oil flow stops, residual oil in the primary system may maintain only momentary lubrication.
To the end of sustaining lubrication after primary oil flow stops, secondary oil systems have been proposed wherein a secondary flow of oil from a stationary reservoir on the engine is directed to the bearing. In such systems, gravity, air pressure or ejector generated suction induces the secondary oil flow. A new and improved secondary oil system according to this invention incorporates a reservoir for the secondary oil which rotates with the rotor shaft whereby centrifugal force induces secondary oil flow.